11-12 120 Series Maternal/Fetal Monitor Revision B
2015590-001
Peripheral Devices: Model 115-Compatible Communications Protocols
Fetal Movement
This field contains one ASCII character representing the current status of the FM
signal: low or high. If the data byte is a 0 (30H), then the signal is low indicating no
movement is detected; if the data byte is 1 (31H), then the signal is high indicating
fetal movement is detected. If the fetal movement feature is not in the monitor, the
data byte is 2 (32H). If the fetal movement feature is present but not enabled, the
data byte is 4 (34H). This data is transmitted four times per second. (Fetal
movement detection circuitry is an option which can be purchased for the 120 Series
Monitor. Refer to the 120 Series Monitor Service Manual for more information.)
Recorder Status
This field contains one ASCII character representing the current status of the PAPER
OUT*
signal: low or high. If the data byte is a 0 (30H), then the signal is low
indicating paper is loaded and the recorder door is closed; if the data byte is 1 (31H),
then the signal is high indicating a paper out condition. This data is transmitted once
per second, when active.
End of Text
This 1-byte field contains the value 03H. If this byte is sent immediately following
the Monitor ID, then the 120 Series Monitor will cancel transmission of all data.
Limitations
The only restriction on the information transmitted during either 115
communication mode occurs when the baud rate is set below 4800 baud. Under this
condition, data loss may occur.
NOTE: The recommended baud rate is 9600.
Error Conditions
Transmission Errors
Transmission errors may be detected by the external computer as parity errors,
framing errors (no valid stop bit), or invalid characters. There is no facility in the
120 Series Monitor to re-transmit any information found to contain an error. It is
therefore up to the user to decide what action to take as a result of an error.